Search Results

Common bean (Phaseolus vulgaris L.) was introduced in Europe from both Mesoamerican and Andean centers of origin and has been cultivated in central Europe for centuries. The first objective of this study was to evaluate genetic diversity and the population structure of 167 accessions divided into four groups according to geographical origin (Slovenia and Austria) and time periods (historical and present) using 14 simple sequence repeat (SSR) markers. The second objective was to improve our understanding of the pathways of dissemination and the evolution of this species in central Europe. Great allelic polymorphism was detected in all four groups of examined accessions, indicating that Slovene and Austrian bean germplasm in the past possessed significant variation that has been well preserved until today. In factorial correspondence analysis, accessions from different groups clustered together indicating potential gene flow between countries. The uncovered diversity corresponded very well to the two recognized gene pools (Andean and Mesoamerican). The majority of accessions in every single group belonged to the Andean gene pool. Strong predominance of Andean genotypes classifies Slovenia among other Mediterranean countries, like Spain and Italy. The latter appears as a most probable source of first beans in Slovenia and Austria. We assume that in the beginning of the previous century after very tight relationships between Slovenia and Austria loosened, introgression of genotypes from western and northern European countries took place in Austria, which resulted in a very high proportion of Mesoamerican genotypes that we found in the present Austrian germplasm (44%). Several putative hybrids between the Andean and Mesoamerican gene pools were detected in this study. Evolutionary significance, origin, and breeding potential of these recombinants are discussed here.

There is a long tradition of common bean cultivation in Slovenia, which has resulted in the development of numerous landraces in addition to newly established cultivars. The genetic diversity of 100 accessions from the Genebank of the Agricultural Institute of Slovenia (AIS) were evaluated with amplified fragment length polymorphism (AFLP) markers and phaseolin seed protein. Twenty-seven standard accessions of known Mesoamerican and Andean origin, 10 wild Phaseolus vulgaris accessions and two related species, P. coccineus L. and P. lunatus L., were also included. Ten AFLP primer combinations produced 303 polymorphic bands, indicating a relatively high level of genetic diversity. Based on the marker data, unweighted pair group method with arithmethic mean (UPGMA) analysis and principal coordinate analysis (PCoA) all P. vulgaris accessions were separated into three well-defined groups. Two groups consisted of accessions of Mesoamerican and Andean origin, while the third was comprised of only four wild P. vulgaris accessions. A set of Slovene accessions formed a well-defined sub-group within the Andean cluster, showing their unique genetic structure. These data were supported by phaseolin analysis, which also revealed additional variants of “C” and “T” phaseolin types. The results are in agreement with previous findings concerning diversification of common bean germplasm introduced in Europe.

In this study, genetic diversity of 119 accessions of common bean (Phaseolus vulgaris) from five former Yugoslav republics constituting the western Balkans was assessed by 13 microsatellite markers. This set of markers has proven before to efficiently distinguish between bean genotypes and assign them to either the Andean or the Mesoamerican gene pool of origin. In this study, 118 alleles were detected or 9.1 per locus on average. Four groups (i.e., Slovene, Croatian, Bosnian, and Serbian) showed similarly high levels of genetic diversity as estimated by the number of different alleles, number of effective alleles, Shannon’s information index, and expected heterozygosity. Mildly narrower genetic diversity was identified within a group of Macedonian accessions; however, this germplasm yielded the highest number of private alleles. All five germplasms share a great portion of genetic diversity as indicated by the analysis of molecular variance (AMOVA). On the basis of the scored number of migrants, we concluded that the most intensive gene flow in the region exists in Bosnia and Herzegovina. Cluster analysis based on collected molecular data classified the accessions into two large clusters that corresponded to two gene pools of origin (i.e., Andean and Mesoamerican). We found that Andean genotypes are more prevalent than Mesoamerican in all studied countries, except Macedonia, where the two gene pools are represented evenly. This could indicate that common bean was introduced into the western Balkans mainly from the Mediterranean Basin. Bayesian cluster analysis revealed that in the area studied an additional variation exists which is related to the Andean gene pool. Different scenarios of the origin of this variation are discussed in the article.